RESUMO
Objective To observe the pulmonary pathologic changes of endotoxin (ET)-induced acute lung injury (ALI) in rabbits and the potential protective effects of fructose-1,6-diphosphate (FDP) on the ET-induced ALI of rabbits. Methods 24 flap-eared albation rabbits were randomly assigned to 3 groups, 8 for each, as follows: control group (group A), ET-treated group (group B) and combination group (treated by ET and FDP, group C). ALI was induced by injection of ET at one time. Group A was only injected with placebo, normal saline. ET was given to the rest groups. In group C, FDP was given as an intervening measure after rabbits injured. Rabbits were sacrificed at 6h time point. The pulmonary pathologic changes were observed. Some markers of pulmonary tissues, including the content of lipid peroxide (LPO), thromboxane B2 (TXB2), 6-keto-prostaglandin F1α(6-keto-PGF1α), interleukin-13 (IL-13) and the activity of superoxide dismutase (SOD), were observed. Results Compared with group A, the contents of LPO and TXB2 of group B showed significant increase (P＜0.05, P＜0.01), the SOD activity of group B weakened obviously (P＜0.01), the contents of 6-keto-PGF1α and IL-13 showed no statistical differences. The LPO content and the SOD activity of group C were similar to those of group A, the contents of TXB2, 6-keto-PGF1α and IL-13 of group C were much higher than those of group A (P＜0.01). Estimated by light microscope and electron microscope, the structure of lung tissue of group A is basically normal, the pathologic injuries of lung tissue of group B were much more severer and that of group C were slighter. Conclusion In the progress of ET-induced ALI, the oxidative injury, imbalance of TXB2/6-keto-PGF1α ratio and the secretion deficiency of protective cytokines play important role in inducing pathologic injuries of lung tissues. FDP can inhibit oxidative injury, ameliorate TXB2/6-keto-PGF1α balance and promote the secretion of protective cytokines, which, in turn, can protect rabbits from ET-induced ALI to some extent.
RESUMO
Objective To investigate the expression of matrix metalloproteinase-2 (MMP-2) mRNA in lungs of rabbits with acute lung injury (ALI) induced by endotoxin (ET) and the effects of meloxicam in its treatment, and to explore the protective mechanism of meloxicam. Methods Twenty four Japanese flap-eared white rabbits were randomly assigned to three groups: control group, ET-challenge group and meloxicam-treatment group. There were eight rabbits in each group. ALI model of rabbits was replicated with intravenous ET injection (700?g/kg weight), and meloxicam (2.5mg/kg weight) was intravenously given afber ET challenge in the treatment group. During the experiment, arterial blood gases, lung wet/dry (W/D), lung water content, the pathologic changes in lung, the expressions of MMP-2 mRNA in the lungs were determined. Results Compared with control group, oxygen saturation index (PaO_2/FiO_2) was significantly decreased and pulmonary edema, hemorrhage, extensive inflammatory cells infiltration were observed in ET group. The lung wet/dry (W/D), lung water content and the expressions of MMP-2 mRNA were significantly higher in ET group than those in control group. In meloxicam-treatment group, PaO_2/FiO_2 remained in normal range, and the lung wet/dry (W/D), the lung water content and the expressions of MMP-2 mRNA were significantly lower than those in ET group. The pathologic changes in lung tissues were not severe in group C. Conclusion The up-regulation of MMP-2 mRNA expression was observed in ALI animal model. Meloxicam could down-regulate MMP-2 mRNA expression, producing protective effects on ALI induced by ET in rabbits.
RESUMO
Objective To investigate the changes in interleukin-19(IL-19)in lungs of rabbits with acute lung injury(ALI)induced by endotoxin(ET),so as to study the mechanism of injury of ET to the lung and the protective mechanism of meloxicam.Methods Twenty four male Japanese flap-eared white rabbit was randomly assigned to three groups:control group,ET-treated group and treatment with meloxicam group.Rabbit ALI model was replicated with intravascular ET injection(700?g/kg),and meloxicam was intravenously injected(2.5mg/kg)for treatment group.The content of IL-19 was measured with ELSIA method and the changes in malondialdehyde(MDA)and superoxide dismutase(SOD)were determined in every group.Results IL-19 expression in ET challenged group was significantly higher than that in control group(P